X Marks the Spot

When using autosomal DNA, the X chromosome is a powerful tool with special inheritance properties.  Many people think that mitochondrial DNA is the same as the X chromosome.  It’s not.

Mitochondrial DNA is inherited maternally, only.  This means that mothers give their mitochondrial DNA to all of their children, but only the females pass it on.  So tracking mitochondrial DNA back up your tree, it goes to your mother, to her mother, to her mother, until you run out of direct line mothers on that branch.  The mitochondrial DNA is shown by the red shading below.  The Y chromosome is blue.

Mitochondrial DNA is not one of the 23 chromosomes you obtain from both of your parents.

The X chromosome is different.  The X chromosome is one of the 23 pairs of chromosomes.  The 23rd pair is the pair that dictates the gender of the child.  If a child has an X and a Y, it’s a male.  Remember that the father contributes the Y chromosome to male children only.  If the child has two X chromosomes, it’s a female.

The inheritance patterns for the X chromosome for males and females is therefore different.  Men inherit only one X chromosome, from their mother, while women inherit two Xs, one from their mother and one from their father.  In turn, their parents inherited their X in a specific way as well.  All ancestors don’t contribute to the X chromosome.

In my paper published in the Journal of Genetic Genealogy (Vol. 6 #1) in the fall of 2010, in a paper titled Revealing American Indian and Minority Heritage Using Y-line, Mitochondrial, Autosomal and X Chromosomal Testing Data Combined with Pedigree Analysis, in addition to other types of analysis, I analyzed my X chromosome and what it told me about where some of my Native and African inheritance came from.

At that time, the only company returning ethnicity information about the X chromosome was deCode genetics.  My X chromosome showed that I carried Native American heritage on the X chromosome as well as on some other chromosomes.

I’m going to share the part of this paper involving the X chromosome and how it can be used genealogically and in particular, to identify candidates who could have contributed this Native and African ancestry.

Blaine Bettinger granted me permission to use 2 charts in the paper and again for this blog.  Thanks much, Blaine.  He originally published them on his blog, The Genetic Genealogist, in December 2008 and January 2009 in his blogs about how to use the X chromosome for genealogy.

The first chart shown below is the male’s X chromosome inheritance chart.  You can see that he only obtains his X chromosome from his mother who inherited it from both her mother and father, but only from some of her ancestors on either side.

The next chart is the female’s inheritance chart.  She obtains her X from both of her parents.

Blaine color coded these, pink for females and blue for males, so I was then able to quickly use them to fill in my ancestor’s names.  I know this next chart looks messy, but it’s what I did and I still refer to this regularly.  I don’t’ expect you to READ this, I expect you’ll DO something like this with your own pedigree chart.  So excuse the look into my messy closet:)

I numbered the slots so that I could work with them later.

The results were quite surprising.  The first thing that became immediately evident is that I didn’t have to worry about a few lines.  On the chart below, you can see that my mother’s German lines could be immediately eliminated, because we know they were not the source of the Native American heritage.

This leaves only three individuals on the mother’s side as candidates for Native ancestry.  Those are the numbered slots between the German lines.

The people below correspond to the numbered slots above.  See, I told you that you didn’t need to read the chicken scratch chart.

5 – Naby (probably short for Abigail), last name unknown but may be Curtis, born in Connecticut in about 1793.

7 – Capt. Samuel Mitchell, born probably about 1700, possibly in Kittery, Maine or possibly in Europe, mother unknown.  This line is probably eliminated.

8 – Captain Mitchell’s wife, Elizabeth, last name unknown

Using the pedigree chart, we narrowed the mother’s side from 21 possible slots to 5 with one more probably eliminated.  Of these, mitochondrial DNA sampling of the descendants of the two women whose last name is unknown would produce the answer to the question of maternal Native or African ancestry.

The father’s side is more complex because many of his ancestors immigrated in the colonial era.  Candidates for Native ancestry are as follows:

20 – Mary, wife of John Harrold (Herrald, later Harrell), born about 1750, died in 1826 in Wilkes County, NC.  She was rumored to have been Irish.

21 – Michael McDowell, born 1747 in Bedford Co., Va. – his mother is unknown.  His father was a second generation immigrant who lived in Halifax and Bedford Counties in Virginia.

22 – Isabel, wife of Michael McDowell, probably born about 1750, surname unknown, located in Virginia.

27 – Elizabeth, born about 1765, wife of Andrew McKee of Virginia.

28 – Agnes Craven is the last slot on the chart, but not the last in the line.  Her father was Col. Robert Craven born 1696 in Delaware and was well to do.  His mother is unknown.  Robert’s wife was Mary Harrison, born in Oyster Bay, New York to Isaiah Harrison and Elizabeth Wright.  These lines appear to reach back to Europe but are unconfirmed, probably eliminating these lines.

30 – Phoebe McMahon, wife of Joseph Workman, born 1745 York Co., Pa, daughter of Hugh McMahon, mother unknown.

31 – Gideon Faires’ mother was Deborah, born 1734, possibly in Augusta Co., Va.

32 – Sarah McSpadden’s father was Thomas McSpadden born 1721 in Ireland, eliminating this line.  Sarah’s mother was Dorothy Edmiston whose father was born in Ireland, eliminating that line.  Dorothy’s mother was named Jean and was born in 1696 but nothing further is known.

33 – Martha McCamm, born before 1743, wife of Andrew Mackie of Virginia, parents unknown.

On the father’s side, we began with 13 slots, positively eliminating one and probably eliminating a second, leaving 11.  Of these, 7 could be resolved on the maternal line by mitochondrial DNA testing.  Taken together, this side of the pedigree chart is a much better candidate for both Native and African DNA sources.  Notice all of the females who have no surnames.  These are excellent places to look for Native ancestry.  On my chicken scratch version, these are highlighted in yellow.

While the X chromosomal pedigree chart analysis is not the perfect scenario, the pedigree chart has 128 slots.  Using the X chromosome narrows the candidates to 34 slots.  Genealogy narrowed the slots to 15 and focused mitochondrial DNA testing could narrow them to 6.  Further genealogy research on those ancestors could potentially eliminate them by placing them “over the pond” or by discoveries which would facilitate DNA testing.

Marja and Me

You might recall that Marja and I are also related on our X chromosome.  In this case, since she is from Finland, the probabilities are exactly the opposite.  It’s much less likely that our connection is on my father’s or mother’s British Isles lines, and much more probable that it’s through my mother’s German lines. The early colonial settlers tended to be from the British Isles and certainly the people filling the X chromosome slots from my father’s side appear to be, with names like McDowell, McSpadden, etc.

Mother’s Anabaptist line (Brethren) is the German grouping through my mother’s father and descends from France and Switzerland,although these particiular lines don’t appear to have become Brethren until after immigrating to America.  Marja also has other matches with people from the Anabaptist project.

Those end-of-line people are:

  • Barbara Kobel – born 1713 probably Scholarie Co., NY
  • Anna Maria Deharcourt – born 1687 Muhlhofan, France, died Oley Valley, Berks Co., Pa., probable parents Jean Harcourt and wife, Susanna
  • Veronica – wife of Rudolph Hoch, born 1683 Basel, Switzerland, died 1728 Oley Valley, Berks Co., Pa.
  • Susanna Herbein – born 1698, Switzerland, father Jacob, died 1763 Oley Valley, Berks Co., Pa.
  • Jacob Lentz – born 1783 Wurttemburg, Germany, died 1870, Montgomery Co., Ohio
  • Fredericka Moselman – born 1788 Wurttemburg, Germany, died 1863 Montgomery Co., Ohio

Mother’s Dutch line is eliminated, because it’s through her father’s father.  Marja and I thought that might be a possibility, but we can see from this chart that it is not.  My father also has a Dutch line that was eliminated because it came from his paternal line.

Mother’s Lutheran Palatinate line, end-of-line ancestors show below, is though Mother’s maternal line.

  • Johann Jacob Borstler – born about 1659 Beindersheim, Bayern, Germany
  • Anna Stauber – born 1659, Schaeurnheim, Germany, father Johannes Stauber
  • Johann Peter Renner – born 1679, Mutterstadt, Bayern, Germany
  • Anna Catherina Schuster – born about 1679 probably in Mutterstadt, Germany
  • Maria Magdalena Schunck – born 1688 probably Mutterstadt, Germany, father Johann George Schunck
  • Johann Martin Weber – born about 1700 Mutterstadt, Germany
  • Rudolph Sager and wife Elizabetha – born about 1669 Ruchheim, Bayern, Germany
  • Rosina Barbara Lemmert – born 1669 Mutterstadt, Bayern, Germany
  • Anna Blancart – born 1642 Mutterstadt, possibly French
  • Johann George Hoertel and wife, Anna Catharina – born about 1642, Mutterstadt, Bayern, Germany
  • Matthaus Matthess – born 1695/1715 Rottenback, Bayern, Germany, wife unknown
  • Anna Gerlin – born 1697, Windischerlaibac, Bayern, Germany
  • Johannes Buntzman – born 1695/1720 Fulgendorf, Bayern, Germany
  • Barbara Mehlheimer – mitochondrial line J1c2 – born 1823 Goppsmannbuhl, Bayern, Germany, mother Elizabetha, unmarried

Note that the mitochondrial line is indeed one of the lines that contributes to the X chromsome inheritance path, but only one of many.

So Marja, it looks like we have to be related through one of my British Isles ancestors, listed in the first part of this article, or from one of Mother’s two German groups.  Personally, I’m betting on the German groups, but you never know.  DNA is full of surprises.

The good news is that my mother’s information is also at GedMatch, along with mine and Marja’s, so by process of elimination, we can at least figure out whether to focus on the pink or the blue side of my chart.

Today, downloading your raw results to GedMatch, combined with Blaine’s X charts above, is really the only good way of working with X chromosome matches.

I’m planning to package this article as a pdf file and send it to my X chromosome matches.  You can substitute your information for mine and do the same thing.  Hopefully, your matches will then understand the X chromsome, its unique inheritance properties, and will provide their X end-of-line ancestors for you as well.



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349 thoughts on “X Marks the Spot

  1. I wish I had studied more biology, I took the dna test thinking that I would find my native American ancestors. I see now that it is not as easy as all that. I found so many great surprises otherwise, and I wish I could afford some further testing. I have narrowed my search however, I would like to know my percentages more precisely on both the Y and the X lines. I wonder at the stories of all my ancestors. One thing that does really amaze me is that people can be descended from the same ancestor more than once. I am also descended from several brother and sister lines. As I followed my lines back, I see that my mothers family and my fathers family have intersected several times in history. It is amazing to me that in the court of Henry VIII, that I descend from at least 6 people that were prominent people to Henry, including Henry and his sister. LOL Now I have a book stuck in my head. Thank you Roberta for doing these explanations, as they are well worded and not quite so hard to follow in our quests.

  2. Thank you for the blog post and the wonderful chart. I have printed off the female one and intend to use it for my X-DNA inheritance.

    Margaret Jordan

  3. How did you know that you and Marja were related on the X chromosome? How can we tell who is related to us on the X chromosome? That information isn’t given in our FF Chromosome browser since it only has 22 chromosomes. What am I missing here???

  4. A very interesting article Roberta – it explained a lot of things. Can you please tell me how we can tell on the X chromosome whether we have a significant match? Is it the total shared cM? Or is it the length of the longest matching segment? What length is considered significant? In the autosomal matches we look for matching segments over 7 cM. What is the magic number on the X chromosome, to be considered a significant match genealogically?

    • The guidelines for the X are the same. 7 cM represents a likely ancestor connection. 5-7 is a good maybe, especially if there is some paper documentation that backs it up. Less than 500 SNPs is considered probably identical by state without anything else. I think Tim Janzen likes to see 700 SNPs and more than 7 cM. Having said that, of course if you have a match above that threshold, then the smaller matches are more likely to be by descent instead of by state. By state means that you share a general population and by descent means you share a common ancestor in a genealogical timeframe.

      • Thank you for your help in understanding this. May I ask another question? When I sort my X Gedmatch results by total shared cM, my top 10 results range between 60.2 and 86.9 cM with largest segments mostly over 10 cM and up to 17.9 cM. But all the 10 XDNA matches have 0 in the autosomal side. How can this be? And what is the significance? (Incidentally, a match with one of your kits comes in at 11 cM and 57.9 shared total – also with 0 on the autosomal side.)

    • Regarding the autosomal ), it sounds like a bug to me. You need to contact John or Curtis at GedMatch and ask them.

      Regarding what is a good match, it’s both the cM length, generally over 7, and the total number of SNPS in that segment, generally over 500.

  5. Hi Roberta,
    Thanks for this clear explanation of X DNA. I have a question I hope you may be able to help me with, my Dad and I both have a match with a woman whom I believe she is probably related through my paternal grandmother’s ancestors from a particular county in Ireland where all this woman’s known ancestors also lived. Using the X chromosome inheritance chart, my Dad could have potentially inherited X DNA from those ancestors. However, on Gedmatch my Dad shows just one matching section on the X chromosome 4.0 cM/387 SNPs with this woman, while I show eight matching sections over 3 cM including 7.8 cM/751 SNPs and 7.1 cM/545 SNPs. Does this mean I am also related to this woman through my maternal line? Thanks for insight you can offer.

    • Remember when you’re dealing with segments this small, unless you have a confirmed ancestor, you could very likely be dealing with segments that are identical by state, not by descent. In your case, if you didn’t receive them from your Dad, then you received them from your Mom, or a segment from your Mom and a segment from your Dad happen to be side by side and therefore “look” like a larger segment. When you’re dealing with small segments, below 7 or minimally 5 cM and below 700 or minimally 500 SNPs, you are likely dealing with segments that are identical by state and there will be more of those in any given population than there will be segments identical by descent. After all, as you mentioned, if they are from Ireland, they came from the same population and likely shared ancestors long ago.

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  7. Thank you for this informative article, and – actually – for all of your articles. Bettinger’s charts are easy to understand, but I still have what’s probably a dumb question: When the mother passes along an X chromosome to her child, is it a new combination of her own two X chromosomes, or is it a copy of either the one she got from her mother *or* the one she got from her father? Thanks!

    • Hi Lynnette. Nope, you can’t assume. It’s certainly a possibility, but it’s also a possibility that they could share pieces of the X, but the DNA simply was not handed down that way. If you have other people proven from the same “X” line, then compare them with the “non-family” person as well. The more people who don’t match at all, then the more likely it is that they don’t share an X ancestor. Good question!

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  9. Maybe this is obvious, but since it wasn’t shown: for the chart with the female inheritance, viewing it clockwise, does the 2nd quarter segment (colored areas, but no percentages) at top left have the same percentages in the same blocks as the 4th quarter segment (last on right side), as shown on the male inheritance chart? Mr. Bettinger’s charts on his site don’t indicate these percentages.

    BTW, I found a blank of these charts at http://dept.cs.williams.edu/~bailey/genealogy/ – the Pedigree Fan chart.

      • Okay, to try to say it more clearly (I hope), if we look at your last fan chart in the article, does the section starting with person #9 and going back have the same percentages as the section starting with person #1, going back? It would seem so, but some of these things can be confusing to me.

        Thanks so much for the article and help.

  10. Is the mtdna x from the mother dominate to the x inherited from the father? Or can a girl inherit genes from both parents equaly? So how do you know which Dna a girl is carring?

    • Neither one is dominant. A female carries an X from each parent and they are entirely independent of each other. Traits themselves can be either dominant or recessive, but they have nothing to do with the X chromosome. Chromosomes are not dominant or recessive.

  11. Thanks for this. I was wondering what I could do with our X-DNA matches. We were surprised to see that my wife’s “Ancestral Composition” shows some possible Native American ancestry, so this may help narrow that down.

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  13. Hello. I am a male. On Gedmatch I have the following matches on the X chromosome for which I do not know what to think:
    – case1: 5.6 cM and 598 SNPs (female match)
    – case2: 7.2 cM and 285 SNPs (female match)
    – case3: 3.3 cM/273 SNPs and 6.8 cM/364 SNPs (female match)
    according to 23andme, the following rules goes for X chromosome:
    Male vs Male : 200 SNPs/ 1 cM
    Male vs female: 600 SNPs/ 6 cM
    according to the rule that I read on this forum (7cM 700 SNPs)
    my questions are:
    – Can I consider any of these ladies a potential genetical match? according to both rules the answer is no!
    – I am right to consider that my closest match is case 1?
    – I read that the general rule of min 5 cM 500 SNPs is accepted but every one now goes for min 7 cM 700 SNPs. what is right?
    – If I may ask an autosomal question, what about a match with 8.8 cM and 696 SNPs or 6.8 cM 1300 SNPs? are they matches at all?
    Thank you very much for your answer.

    • The reason there are different “rules of thumb” for autosomal and the X chromosome is that the inheritance path is different so the amount of DNA from an X ancestor that you inherit is different than the normal autosomal inheritance here you divide every generation by 50%. http://dna-explained.com/2012/09/27/x-marks-the-spot/

      Remember that these are all “rules of thumb” too, trying to help people determine what is real in a genealogical timeframe versus what is population which means from further back in time and not necessarily attributable to a specific ancestor, although that’s isn’t always the case.

      Also, it really isn’t male vs female match. Some males may not qualify at all for consideration as a match to your specific X chromosome. If they come from a part of your tree where you do not inherit an X, for example. If you are a male, then that is anyone on you father’s side of the tree, for example.

      Different companies set different “rules of thumb” too, the 7.7 vs 5cM and the 500 vs 700 SNPs. It’s pretty much universal that below 5, it’s not useless, but it’s less and less likely the smaller you get in terms of SNPS and in terms of length of cM that match.

      So this is not an absolute – this is a sliding scale and using the X, it depends on who and where in the tree. So, these three people are all genetic matches to you. They do match you. The question is how far back in time an can you find a common ancestor? Do they match you because you come from a common population, say German, for example and you’re all carrying some DNA that has been in that population for a long time, or is it because you share a common ancestor in more recent times? These tools, plus your genealogy will help to answer that. Mapping certain chromosome segments of yours to known ancestors will go a long way to helping to answer some of these questions as well.

  14. Thank you for the answer. My quest is somehow harder than the average european since i come from a french island where admixing has been a way of life for centuries now. I am the result of mainly europeans (french, english, portuguese, spanish and italian) who mixed with malagasy (african + asian) and indians. This makes us genetically very rich but does not allow us to go beyond our acestors that traveled and settled on our island. As for me I end up matching very closely some specific europeans such as german, austrian, roumanian, etc or some russians or even some ashkenazim. I have no clue how it can be possible. Most europeans I match with values above 8 cM up to 16 cM and above 700 SNPs which would seem real matches according to the rules. Most askenazim I match at values like 6.8 cM 696 SNPs, very close to the minimum but not just it. All this made me wonder if the matches below 7 cM 700 SPNs but yet very close to the limit like my ashkenazim matches, if is was meaningful! Thank you again.

    • Ashkenazi and other heavyily intermarried people are a bit of a different situation. In essence, by continually intermarrying, they pass the same DNA around and back and forth, with little new admixture to add to the pot. So people from endogamous societies will show more matches that are really more distant than they appear, because as a group they carry so much of the same DNA.

  15. I’m just trying to get this straight in my head. A female can pass her X chromosome and also her Mitochondrial DNA,the only difference is that the X chromosomes determine the sex?So a female can inherent her mothers Mitochondrial DNA,and also inherent her Fathers X chromosome that he received from his mother?

    • Actually, the thing that determines the sex of the child is whether the father passes his X chromosome or his Y. If he passes a Y, it’s a boy, and if he passes his X, it’s a girl. The mother always passes an X chromosome to both sexes of children and she also passes mitochondrial DNA to both sexes of children as well.

  16. Great article — thank you very much for taking the time to write it as well as answer our questions.

    Here’s a question that does not appear to be addressed:

    I’m male and adopted. I have a female match who is my longest segment of all my matches at GEDcom, FTDNA, and 23andMe (32.7 cM), and is the person I share the most DNA with (63.4 cM) at all of the aforementioned groups. Further, GEDmatch has us with relatively small levels of X-DNA; on the order of sibling level –> to my birth mom does not explicitly fit the male/female sequence of siblings and descendants to my possible birth mom, I can immediately remove that branch as a search branch (no way for her XDNA to get to me). This obviously will narrow down the choices in walking the descendants, which is highly desired because many of the people at the MRCA or sibling levels in the 1800’s and 1900’s were amazingly fertile.

    4) With respect to my father, any GEDmatch or 23andMe listing of X-DNA immediately restricts those people with atDNA AND XDNA matches to my maternal side. Put another way, any surnames that arise from a XDNA match CANNOT be directly tied to my paternal side.



    • Paul,
      Why couldn’t her X DNA be on your paternal side? You could be her maternal relative and she can be your paternal relative.
      Or what if she’s related to your fathers mother?. I have matches from both sides,Mothers mother and mothers father to fathers mother and fathers father.

      • Hello August,

        If I’m at the center of the Pedigree Chart, and because I’m male, the way I interpret this is that because the male (my father) does not give me a X chromosome, then the only path to me via X DNA is on my maternal side.

        It appears my list of questions 1-3 above were truncated:

        “Please confirm the following:

        1) A match with XDNA, but no match on atDNA, means nothing. I have several 23andMe XDNA listings but they do not have atDNA segment overlaps on chromosomes 1-22. Same at GEDmatch.

        2) Because I match a female with atDNA as well as XDNA, I can use the female pedigree chart for x-DNA as well as her ancestry tree to map back to our MCRA level, filling in the blocks backwards towards the MRCA possibilities.

        3) Since I am looking for my birth mo, from the perspective of a new pedigree chart with my mom at the center and only our MRCA known, because I match a female with atDNA and XDNA I can map a path to my mom (in the center) from the MRCA level using the XDNA pedigree chart. Put another way, if the path from the MRCA –> sibling level –> to my birth mom does not explicitly fit the male/female sequence of siblings and descendants to my possible birth mom, I can immediately remove that branch as a search branch (no way for her XDNA to get to me). This obviously will narrow down the choices in walking the descendants, which is highly desired because many of the people at the MRCA or sibling levels in the 1800’s and 1900’s were amazingly fertile.”

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  18. Okay, so let me see if I understand this correctly…I took the Ancestry Autosomal dna test and uploaded my raw file into GEDmatch. I’m mainly interested in my paternal line (I was adopted) since i already know all I want to about my maternal line. So, based on that, I should focus on Autosomal matches that have no X-dna match, correct?

    Thank you!

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  20. I’m still confused, but think I get it. But to confirm, being female, if my dna shows native american ancestors, that ancestor can only be a mother of a mother of a mother?

  21. Thank you so very much for your work and explanations. Can I ask several stupid questions here?

    1) I’m really sorry but I don’t understand clearly what it means if I have with autosomal testing on GEDmatch: X chromosome with a male ?

    2) What it means if I have with autosomal testing on GEDmatch: X chromosome with a female?

    3) Does the XDNA also have to have more than 7 cMs to be “by descent” ?

    Obviously, I’m still in the baby stage here. Thanks for any clarity.

    • No, it does not have to be over 7cm to be by descent, but it improves the chances quite a bit. Matching a male or female means you share a common ancestor sometime back in time. The inheritance pattern is different for men and women, which is why I provided the pedigree maps. It helps the two people who match to determine which lines their match may have come from.

    • My brother and I have both received results of our DNA from the Genographic program, but I’m not sure what it is telling us. Mitachondrial is H5a2 and his shows I-L22  There is not too much difference in the rest of the information – Northern European 44% vs. 46%; Mediteranean both 35%; Southwest asian 19% vs 18%-except that mine shows 2% Native American and his does not show any.  Is this difference possibly just because of the splits in DNA as they are passed from generation to generation? I am tracing our geneology and am questioning how to search for the 2% Native American.  Can I assume that could have been from maternal or paternal ancestors or should I just be checking my maternal line (and only the females or the males in that line also?)  This is all bewildering to me so any advice you can give will be most helpful.


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  23. Hi there! I am a female with a female match on 23andme with 22cm on the X chromosome and 0 on the autosomals. I’m not sure what that means? Thanks for your help!

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  26. Hi Roberta,
    Thanks for your wonderful explanations of DNA that help demystify a complex subject. While reading your article: X Marks the Spot, I was pleasantly surprised to discover that we are distant cousins. Joseph and Phoebe McMahon Workman are my 6th great-grandparents. I checked on Gedmatch and if you are *Betty (A830810), we match genetically, as well as, genealogically. This has been one of my greatest joys of genealogy- finding the unexpected cousin. Thanks, Bonnie

  27. Hello, I came across the earlier reply I have the same question,

    Thank you for your help in understanding this. May I ask another question? When I sort my X Gedmatch results by total shared cM, my top 10 results range between 60.2 and 86.9 cM with largest segments mostly over 10 cM and up to 17.9 cM. But all the 10 XDNA matches have 0 in the autosomal side. How can this be? And what is the significance? (Incidentally, a match with one of your kits comes in at 11 cM and 57.9 shared total – also with 0 on the autosomal side.)
    Is there still a bug? Also generation wise is a generation approx 20 years ….Well thank you so much for all you do you are changing so many lives thank you !

  28. Hello, Concerning the X that is inherited from your father, would that be from his Mother’s Mom, and her Mom so on and also from his Father’s Mom, and her Mom and so on,

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  30. If I have an autosomal match who is female (I am also) and she is NOT an Xmatch, does that automatically mean that we are related through her Father’s/Father’s line??

  31. My brother and I have only 3 short matching segments on the X chromosome: 3.85, 10.23, and 10.68 cM. Can I infer from this that I may have largely inherited my paternal grandmother’s X? I have read that X inheritance in females can be very uneven from maternal and paternal sides.

    • There are actually 3 Xs in play here. One from your father and 2 from your mother – for you. Your brother of course only got the ones from your mother. Your mother’s 2 Xs would have combined to give both you and your brother part of her parents Xs. So both of you inherited some portion of her 2 Xs. You obviously inherited an entire X from your father, which came from his mother – but that has nothing to do with your brother. The piece you match your brother on came from your mother – from the recombined X you both got from her. What you can say is that one of you inherited most of the X from her mother and the other one from her father.

      • Of course! Thanks so much. Clearly I didn’t think about what my matches were actually being compared TO. Thanks for sending me down the correct path. You’re the best.

  32. Roberta,

    You have a great blog, and this is a particularly informative and useful article. At the time you wrote it, it was true that AncestryDNA results could not be downloaded from AncestryDNA and uploaded to GEDmatch, but that is now no longer the case. If possible, you might want to edit the original article accordingly so that any would-be AncestryDNA users who could benefit from GEDmatch and in so doing also contribute to the benefit of other GEDmatch users, don’t become unnecessarily discouraged from checking out that capability. I’m sure you’ve probably addressed that somewhere, but can you edit it here, too?


  33. Roberta, I have a female cousin match (I’m female as well) with 7 matches on the x chromosome (total 29.9 cM greater than 3cM; 2 segments being 5.1 cM each). We also share significant autosomal DNA – matching on 4 chromosomes for total of 94.4 cM (largest match being 33.8 cM). Does the fact that we share x matches automatically exclude a relationship path that passes from male to male? Couldn’t the autosomal matches allow for that possibility?

    I believe we are second cousins once removed. (She is a generation older than me) The only possible relationship path I can deduce is that my mother’s father’s parents were the siblings of her mother’s grandparents (a case of two sets of siblings marrying). But that would mean that the path would run through two males.

    Apart from my own maternal grandfather – my tree is well documented as is hers. So again this is the only path I see. Is this plausible?

    Thanks for your help!

      • Thanks for your prompt reply. That’s disappointing since I thought I had finally broken down that brick wall but better to know for sure. Just to be clear, when you said that we could be related through two lines – you mean that some of the autosomal DNA matches could be attributed to another line- but in any case, the relationship would always pass through a female since we share x DNA.

        Given the amount of DNA we share, would you agree that that we are most likely 2nd cousins? Or could it be that the kinship prediction could perhaps be thrown off by sharing multiple lines?

          • Thanks, Paul. Yes, I understand that – but I was looking at pathway that went through two males before getting to the female. which I know is not possible with the x. Twist was that we could be related on two sides of her family and we share substantial autosomal DNA so I was hoping that autosomal dna match might work for the male male female path. Looks like not.

          • I am confused then. So an X match does not necessarily correlate to at least a good portion of the autosomal DNA matches?? We share about 95 cM of autosomal DNA and also around 29 cM of X. I was wondering if the autosomal could account for the male male female path and the X perhaps be attributed to another line further down. But I thought that your answer meant that the X match automatically ruled out this scenario.

          • Thanks. I have read several of the articles – but I will reread. I did believe that the two could be from different lines, but one of the FTDNA group administrators insisted that this would not be the case and that the shared x matches (-3-7 cm each) on 7 segments were too significant not to be reflected in the autosomal matches. Does the fact that I do not match her daughter at all -neither x nor autosomal- reveal anything? I know we all inherit different segments,etc so it could be that is the sole explanation.

          • That could be the sole explanation. I would presume the X matches would be reflected in the autosomal, but note the word presume. Have you looked at other people you believe to be from the same line to see if you can triangulate any of this?

          • I have – nothing definitive but likely match for all would be my GGG GM. It looks like I will just have to wait for other matches to come in before I’ll be able to figure it out. Too much missing info at this point – as I have it now, my mother’s father’s mother would be great aunt on this cousin’s maternal side. (Her maternal grandmother’s sister) And my maternal grandfather’s father would be her great uncle -( Her paternal grandfather’s brother). X MRCA would be my GGG GM (Her GG GM) and autosomal MRCAs would be both sets of my GGG grandparents (her GG grandparents).

  34. Roberta, another question on an older post. It appears that you may have been able to paint your X-Chromosome. Is that true, and if so, what tool did you use? I don’t think GEDMATCH.com provides that as an option.

  35. Pingback: Lost in X – DNA that is | Family history across the seas

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  37. Hi. I am an adoptee looking for relatives. On GEDmatch, I have 3 members of the same family (not sure how) that are strong matches on the X. One female at 65.8cM/6552SNPs. One female at 63.2/6472. One male at 63.2/6388 (I believe him to be at least one of the females father). Is this significant in any way?

  38. My mom has a female X-match (rs). RS’s mother is Hispanic from SW USA, and my mom’s family is European from the East coast. So we eliminated RS’s mother as the person providing the matching X to my mom. RS’s father has also tested, and while he is an autosomal match to my mom, he is not an X match. I’m surprised by this. If the X match is thru RS’s paternal grandmother, shouldn’t her father also be an X-match?

  39. Roberta, can siblings inherit a different X from the maternal side, since it is recombined? So could one sibling inherit a portion of an X and not another sibling something from a different portion of an X? I understand that is not possible on the paternal side, since the X stays whole. .

  40. Hi, I’m new to this dna testing. I have problem trying to figure out two dna test that’s marks are so similar to each other. I need help with this brain freeze. Only if you ready to solve a generation curse. I’m married into it, and we have a child together, and I don’t want this confusions for our child. Please help

  41. When using Family Finder on FTDNA and selecting the X Matches option, does it absolutely follow that individuals who are “Common Matches” to your X Matches are also connected on those lines in the PINK boxes on the inheritance chart? If not why not?

      • Roberta

        Sorry I didn’t phrase my question well. I’ve read your articles and I think I understand the pink boxes and X Match theory that individuals in my X matches list are connected on one of the “coloured box” lines in my tree and not on a blank white box.

        I have only 17 X matches – but those 17 people (all female except one?) have common matches to me also. It’s those common matches I’m curious about. If I select one of my X matches and look at the “ICW” on the Common Matches dropdown – can I assume that those Common Matches are connected on the same “coloured” box lines that the X match person is connected on? and can I assume that any “common match” to an X match is on one of my coloured box lines?


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